This invention relates to power shift gears for motor vehicles, a motor vehicle gear as well as a motor vehicle power train.
The overwhelming majority of known vehicles or motor vehicles have either manual auxiliary shafts or automatic gears that are provided with a planetary gear. Also known are power shift gears, such as, for example, parallel gearboxes (PSG), where an auxiliary shaft with two (main) gear shafts is combined with an (automated) actuation in order, for example, to improve the switching comfort and to develop the fuel consumption in a more economical manner.
In such power shift gears or parallel gearboxes (PSG), the engageable and disengageable speeds (as a rule, there are two of them) are divided over two subgears that are connected parallel, and each of which has a main gear shaft. Power shift gears or parallel gearboxes (PSG) make it possible to switch between speeds so as not to interrupt the traction force. It is especially for this purpose that known designs of each of the parallel-connected subgears are connected on the input side via a separate clutch or a friction clutch with the power takeoff shaft of the internal combustion engine. When one of these clutches is disengaged, then, in the pertinent subgear, one can set a target speed, while simultaneously via the other subgear, torque can be transmitted from the combustion engine in the direction of the motor vehicle driving axles, and the clutch to the combustion engine, associated with that subgear, is engaged and vice versa. By engaging the initially disengaged clutch and disengaging the initially engaged clutch in a controlled manner, one can, from the particular output speed of one of the subgears, switch over into a target speed of the other particular subgear, whereby during this gear change process, the disengagement and engagement of the clutches will take place in an overlapping fashion in such a manner that throughout the entire gear change process, torque will be transmitted from the combustion engine to the driving axle.
EP 1422442 A, EP 1422443 A, EP 1422444 A and EP 1422446 A disclose motor vehicle gears that have two parallel-connected subgears and where a planetary gear is provided in each of these subgears.